Lack of viral selection in human immunodeficiency virus type 1 mother-to-child transmission with primary infection during late pregnancy and/or breastfeeding.
Mother-to-child transmission (MTCT) of human immunodeficiency virus type 1 (HIV-1) as described for women with an established infection is, in most cases, associated with the transmission of few maternal variants. This study analysed virus variability in four cases of maternal primary infection occurring during pregnancy and/or breastfeeding. Estimated time of seroconversion was at 4 months of pregnancy for one woman (early seroconversion) and during the last months of pregnancy and/or breastfeeding for the remaining three (late seroconversion). The C2V3 envelope region was analysed in samples of mother-child pairs by molecular cloning and sequencing. Comparisons of nucleotide and amino acid sequences as well as phylogenetic analysis were performed. The results showed low variability in the virus population of both mother and child. Maximum-likelihood analysis showed that, in the early pregnancy seroconversion case, a minor viral variant with further evolution in the child was transmitted, which could indicate a selection event in MTCT or a stochastic event, whereas in the late seroconversion cases, the mother's and child's sequences were intermingled, which is compatible with the transmission of multiple viral variants from the mother's major population. These results could be explained by the less pronounced selective pressure exerted by the immune system in the early stages of the mother's infection, which could play a role in MTCT of HIV-1.
Ceballos
Ana
A
National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
Andreani
Guadalupe
G
National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
Ripamonti
Chiara
C
Viral Evolution and Transmission Unit, DIBIT - San Raffaele Scientific Institute, Milan, Italy.
Dilernia
Dario
D
National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
Mendez
Ramiro
R
National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
Rabinovich
Roberto D
RD
National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
Cárdenas
Patricia Coll
PC
Hospital Juan Fernández, Buenos Aires, Argentina.
Zala
Carlos
C
Hospital Juan Fernández, Buenos Aires, Argentina.
Cahn
Pedro
P
Hospital Juan Fernández, Buenos Aires, Argentina.
Scarlatti
Gabriella
G
Viral Evolution and Transmission Unit, DIBIT - San Raffaele Scientific Institute, Milan, Italy.
Peralta
Liliana Martínez
LM
National Reference Center for AIDS, Department of Microbiology, University of Buenos Aires School of Medicine, Buenos Aires, Argentina.
D000595:Amino Acid Sequence; D001942:Breast Feeding / Q000009:adverse effects*; D017931:DNA Primers; D005260:Female; D015658:HIV Infections / Q000635:transmission*; D015497:HIV-1 / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008895:Milk, Human / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011247:Pregnancy; D011248:Pregnancy Complications / Q000821:virology*; D012641:Selection, Genetic; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014759:Viral Envelope Proteins / Q000235:genetics
D017931:DNA Primers; D014759:Viral Envelope Proteins